Add Mixed Units of Capacity
This Grade 4 Eureka Math skill teaches students two methods for adding mixed units of capacity (liters and milliliters). In the algorithm approach, students add liters and milliliters separately, then regroup 1,000 mL as 1 L if the milliliter sum reaches 1,000. For example, 6 L 750 mL + 3 L 450 mL = 9 L 1,200 mL = 10 L 200 mL. Alternatively, students convert everything to milliliters first, add, then convert back. This skill from Chapter 7 of Eureka Math Grade 4 builds fluency with metric capacity units.
Key Concepts
To add mixed units of capacity, add the liters and milliliters separately. If the sum of the milliliters is 1,000 or more, regroup 1,000 mL as 1 L. An alternative strategy is to convert all units to milliliters, add, and then convert the result back to mixed units.
Common Questions
How do you add mixed units of capacity like liters and milliliters?
Add the liters together and the milliliters together separately. If the milliliter sum is 1,000 or more, regroup: every 1,000 mL becomes 1 additional liter.
What is 6 L 750 mL plus 3 L 450 mL?
Add liters: 6+3=9 L. Add milliliters: 750+450=1,200 mL. Regroup: 1,200 mL = 1 L 200 mL. Total: 9+1=10 L 200 mL.
How do you use the conversion method to add capacity?
Convert all measurements to milliliters, add them, then convert back. For 6 L 750 mL: 6,750 mL. For 3 L 450 mL: 3,450 mL. Sum: 10,200 mL = 10 L 200 mL.
When do you need to regroup milliliters into liters?
Regroup when the sum of the milliliters is 1,000 or more. For every 1,000 mL in the sum, add 1 L to the liter total and keep the remainder as milliliters.
How many milliliters are in 1 liter?
There are 1,000 milliliters in 1 liter. This is the conversion factor used for regrouping in mixed capacity addition.